1. Field of the Invention
The invention relates generally to fiberoptic devices and techniques and, more particularly, to methods for attaching fibers to integrated optics chips and the devices resulting from such methods.
2. Description of the Related Art
Short lengths of optical fibers called "pigtails" are bonded to integrated optics chips to aid in coupling to devices on the chips. Once installed, a pigtail allows fiber-to-fiber splicing to be carried out.
Previous methods for attaching optical fibers to integrated optics chips involve the use of epoxy adhesives or metal-to-metal welding. An example of the latter is the method disclosed in U.S. patent application Ser. No. 006,164, entitled "Microattachment of Optical Fibers," filed Jan. 23, 1987, now U.S. Pat. No. 4,788,406, and assigned to the assignee of the present invention, which application is hereby incorporated by reference herein.
Epoxy bonds tend to be limited by the characteristics of the epoxy (for example, by changes in light-transmitting and mechanical properties in the desired operating temperature range), are slow to set up, and are difficult to use in an automated production environment. Past methods of metal-to-metal welding have involved structurally asymmetric attachment arrangements which result in undesirably high thermal sensitivities of the optical splices. In an asymmetric attachment, the disparity in coefficients of thermal expansion between adjacent dissimilar materials results in thermally-induced stresses on the fiber. It would be a great advance in the art of attaching optical fibers to integrated optics chips if a method could be found which is suited for batch processing and provides a joint which is symmetric and thermally insensitive.